Size of environmental grain and resource matching

For most animals their foraging environment consists of a patch network. In random environments there are no spatial autocorrelation at all, while in fine-grained systems positive autocorrelations flip to negative ones and ba ck again against distance. With increasing grain size the turnover rate of spatial autocorrelation slows down. Using a cellular automaton with forager s having limited information about their feeding environment we examined ho w well consumer numbers matched resource availability, also known as the id eal free distribution. The match is the better the smaller the size of the environmental grain. This is somewhat contrary to the observation that in l arge-grained environments the spatial autocorrelation is high and positive over long distances. In such an environment foragers, by knowing a limited surrounding, should in fact know a much larger area because of the spatiall y autocorrelated resource pattern. Yet, when foragers have limited knowledg e, we observed that the degree of undermatching (i.e., more individuals in less productive patches than expected) increases with increasing grain size .